Clear gate openings of buildings, garages and the like are closed up with sectional gates. In the process, it is common that the sectional gate consists of more than two panel-shaped closing elements (sections), which are led in guide rails by means of guide rollers. The guide rails, which are one-piece as a rule, each have a vertical section in which the rollers of the closing elements are in the closed position, a curved portion connected to this, and a horizontal portion after this in which the rollers of the closing elements are moved for the open position. For most of the sectional gates, the vertical sections are located on both sides of the gate opening and, relative to the gate opening, behind the closing elements so the rollers have to be attached on the back side of the closing elements. The horizontal sections are attached under a ceiling or the like of the building to be closed up, and the vertical and horizontal sections are connected with each other by means of the curved portion.
A sectional gate is known from DE 40 06 912 for which the curved portion, which starts on the side next to the guide rail located at the closing elements at the level of the upper border of the clear gate opening, and for which a weight-counterbalancing mechanism is positioned between the guide rail and the gate opening, and the gate drive takes place through a driven deflection roller of the weight-counterbalancing mechanism. Because the curved portion is above the clear gate opening, the rollers of all of the closing elements are in the closed position in the vertical section of the guide rail. Therefore the surrounding building has to have a high head above the gate opening, so these sectional gates can only be used in relatively high buildings.
A sectional gate is known from DE-OS 22 28 783 for which the guide rail is located behind the closing elements with reference to the gate opening, and the guide rails are laterally arranged in the area of the clear opening. The guide rollers located behind the closing elements guide the closing elements into the vertical closed position, in the process of which the uppermost closing element has to be moved out of a slanted position into a vertical position after the complete lowering of the closing elements by means of an adjusting drive unit. In order to make this movement possible, the guide rail has an opening in the curved portion through which the guide roller of the uppermost section can be swiveled out of the guide rail.
The opening in the curved portion has the disadvantage that the guide rollers of the lower sections can escape from the opening during the lowering of the sections, which can lead to the sectional gate being defective or functioning in a faulty way. Because the guide rails are located within the area of the clear gate opening and behind the closing elements, the sectional gate has to close up a larger gate opening than is useful in the open state. When opening the sectional gate, the upper guide roller has to first be moved precisely back into the guide rail before a force can be applied to move the sectional gate into the horizontal section.
DE 35 08 957 discloses a sectional gate with lateral guide rails located behind the closing elements for which the upper end of the upper closing element is connected with a pivoting lever, which swivels the upper closing element into a vertical position at the end of the closing movement after the upper guide roller hits a limit stop, in order to initiate the swiveling movement of the swivel element on the basis of the lowering movement of the sectional gate. The swivel element is connected with a torsion bar spring, which swivels the swivel element back during the opening of the gate, before the uppermost guide roller moves along the guide rails. The swiveling movement of the swivel element takes place around a fixed turning point situated on the upper edge of the upper section, so the gate has to be lifted as a whole in order to move the upper section into the vertical position.
The task of the invention is to create a sectional gate for which a nearly complete utilization of the clear gate opening is possible in a simple way in the open state of the sectional gate, even with a comparably lower height of the door gate head. A further task of the invention is to make a vertical position of the upper section possible in the closed position, without the functional dependability of the sectional gate being limited during the opening or closing movement.